Comment on the statement that `"` colloid is not a substance but state of a substance `"`

Explanation

The give statement is true. This is because the same substance may exist as a colloid unde certain conditions and as a crystalloid under certain other conditions. For example, NaCl in water behaves as a crystalloid while in benzene, it behaves as a colloids. Similarly, dilute soap solution behaves like a crystalloid while concentrated solution behaves as a colloid (called associated colloid). It is the size of the particles which matters, i.e., the state in which the substance exists. If the size of the particles lies in the range 1 nm to 100 nm, it is in the colloidal state.